1. Field of the Invention
This invention relates generally to device testing and, more particularly, to a method and apparatus for testing devices.
2. Description of the Related Art
Electronic devices are usually tested after their manufacture and before being shipped from the factory. In this context, xe2x80x9cdevicexe2x80x9d may mean an individual integrated circuit, or xe2x80x9cchip,xe2x80x9d or may mean an assembled printed circuit board containing one or more chips. The hardware of such a tester is usually referred to as a xe2x80x9ctest cellxe2x80x9d and usually has some software operating the test cell. The test cell generally includes a number of test heads into which devices are placed for testing. Device testers are designed to test a specific type of device and, so are uniquely adapted depending on the target device type. However, device testers, in many respects, have severely limited capabilities.
One typical limitation regards the number of device types that a tester may actually test. A test cell""s unique adaptation to a particular type of device means that the test cell generally tests that device type well and thoroughly. On the other hand, the unique adaptation prevents the tester from effectively testing any other type of device. Thus, a test cell will usually test only a single type of device.
One approach to this difficulty is to include a variety of different test heads in a single test cell. However, each test head still is limited to testing a single device type. Further, the test cell increases in complexity with the number of different kinds of test heads. In effect, such a test cell is no more than a series of small test cells awkwardly cobbled together.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.
In one aspect of the present invention, an apparatus is provided for testing a plurality of devices. The apparatus, in one embodiment, comprises a controller, a device identifier capable of identifying each one of a plurality of devices as one of a plurality of device types, and a plurality of test heads. Each test head is capable of testing each one of the devices independently of the rest of the plurality of test heads responsive to the identification of each device by the device identifier and under the control of the controller.
In a second aspect of the invention, a method is provided for testing a plurality of devices. The method, in one embodiment, comprises placing the plurality of devices identified into a plurality of test heads, each device being identified as one of a plurality of predetermined device its types and being placed in a respective test head; and directing the testing of each device independently of the testing for the remaining devices responsive to the respective identification of the device, the direction for the testing of each device coming from the same controller.